m(To draw a four sided outline requires four mouse clicks before the close operation: origin, first end point, second end point, and third end point then close to complete the figure back to the origin.)

# Select the file of the freehand drawing [[:File:CarportFreehand.jpg|800px]]

+

# Select the file of the freehand drawing [[:File:CarportFreehand.jpg]]

# position it where you like (e.g. on top of the drawing box)

# position it where you like (e.g. on top of the drawing box)

[[File:CarportExampleWithFreeHand.jpg|800px]]

[[File:CarportExampleWithFreeHand.jpg|800px]]

Line 165:

Line 165:

# select the polyline tool [[File:Polylinetoolselection.jpg]]

# select the polyline tool [[File:Polylinetoolselection.jpg]]

# for each of the three beam polylines you need to

# for each of the three beam polylines you need to

−

## click three times at the positions to get the beam outline

+

## click four times at the positions to get three sides of the beam outline

−

# click "Close" in the tool option bar

+

# click "Close" in the tool option bar to complete the beam polyline back to the origin.

see https://github.com/LibreCAD/LibreCAD/issues/1036 for the question how the close button could be improved

see https://github.com/LibreCAD/LibreCAD/issues/1036 for the question how the close button could be improved

Revision as of 22:04, 2 December 2018

This page presents a simple sequence of creating a basic drawing, from a blank document to a printed design. It assumes that you have installed LibreCAD and have opened it to a new default blank drawing. It introduces quite a few LibreCAD concepts, and links to other pages that explain these.

You can download and unzip File:Carport.zip to compare your results with what the authors of this document saved.

Save the default "unnamed document 1" as "CarportEast" using the "File/Save" Menu

Check that the save was successful by Quitting LibreCAD, and restarting it. The saved file "CarportEast.dxf" should show up in the "File/Recent Files" Menu

Reopen the file and close the "unnamed document 1" by clicking the circled x in the tab.

Scaling

We'd like to have an A4 drawing on which a scaled version of the 5000 x 1300 mm construction fits.

A4 is 297 x 210 mm so if we make the 5000 mm be shown as a 250 mm long line we'd be set. That is a 1:20 scale.

Via the menu Options/Current Drawing Preferences/Dimensions we can set the General Scale to 20 to achieve the scaling. And set Landscape for the paper direction.

Construction lines

The first lines of any technical drawing are the construction lines, setting out the locations of all lines without specifying any line types, colours, etc. All straight construction lines are of 'infinite' length — i.e. they extend off the screen in both directions.

Create a new Construction layer by clicking the "+" sign in the Layer list. The new layer might have a name such as 'construction', and a colour of magenta or cyan or similar. The line's width should be '0'.

Drawing Box

We'd like to create a 5000 x 1300 mm construction line drawing box in which our construction will be placed.
Since we want precise positions for this box we'll use the Command Line Mode and create a Polyline.

Hit space to enter the command line mode - the cursor will jump to the command box (bottom or lower right corner) and "Command" will be in blue (you can type clear in the command box if the state of things is not like that)

Type polyline or "pl" - you'll now be asked for the points

Specify first point: 0.0

Specify next point: 5000,0

Specify next point or [undo]: 5000,1300

Specify next point or [close/undo]: 0,1300

Specify next point or [close/undo]: close

Zoom out with the View/AutoZoom menu item
You should now see a 5 x 1.3 m rectangle at 1:20 scale

Try printing the page with File/Print - the printout should be empty since the construction layer will not be printed

Drawing the frame

For the frame we would like to create three "rectangles" that represent the sides of the frame.
Each side has 40 mm width, so we simply take the three corners of the triangle:

Should you have made a typing error you might want to use the "undo" command to remove the latest drawing item that didn't go as you intended.

You might want to save your result with File/Save.
This time if you print things out with File/Print the result should be visible.
You can also check what the print looks like with File/Print Preview which will open up a new tab

Construction Triangles for Beams

press space to enter the command mode (type clear if you want to get rid of old commands shown)

enter the polygon for the triangle:

pl
0,0
1443,0
@363<104.57
close

The values are from the triangle calculator.

0,0 is the start point

1443 is the x position at which the 363 mm long beam leave the x axis

it leaves at an angle of 75.43 which we have to enter anti-clock wise with makes it 104.57 (90 degrees more than the frames 14.57 angle) the new point is to be calculated relatively so we have used the @ symbol to denote this, the < symbol denotes that we are specifing a polar coordinate.

We repeat this for our other beams

0,0
3359,0
@845<104.57
close
0,0
4174,0
@1050<104.57
close

and end up with:

You'll find a saved version up to this step in the file CarportEastStep2.dxf in the zip file mentioned above.

Drawing the beams

For the beams we could now also calculate the points for the corresponding polygons. We do not need that much precision here so an alternative is to draw the beams with the mouse
using our construction triangles as guiding lines.

Drawing the beams using the mouse

select the default layer again

select the polyline tool

for each of the three beam polylines you need to

click four times at the positions to get three sides of the beam outline

click "Close" in the tool option bar to complete the beam polyline back to the origin.